1Bring a large pot of salted water to a boil. Add the spaghetti and cook according to the package instructions until al dente. Drain and set aside.
While the spaghetti is cooking, heat the olive oil in a large skillet over medium heat. Add the diced onion and sauté until translucent, about 3-4 minutes.
Add the minced garlic to the skillet and sauté for another minute until fragrant.
Increase the heat to medium-high and add the ground beef to the skillet. Cook, breaking it apart with a spoon, until browned and no longer pink, about 5-7 minutes.
Stir in the diced tomatoes, dried basil, dried oregano, salt, and black pepper. Bring the mixture to a simmer, then reduce the heat to low and let it cook for about 15-20 minutes, stirring occasionally.
Once the sauce has thickened, taste and adjust seasoning if necessary.
Serve the Bolognese sauce over the cooked spaghetti and sprinkle with grated Parmesan cheese.